A kind of laser radar optical chip based on micro-ring optical switch network

Abstract

The laser radar optical chip supports multiple working modes, which can form a multi-light path system according to requirements, for example, when the laser radar optical chip contains two input / output couplers and two sets of optical antenna arrays, a double-light-path system is obtained, which can realize field of view splicing and increase the field of view range of the laser radar when all serving as a transmitting end; when all serving as a receiving end, the receiving area is doubled, and the receiving capacity is stronger; when one set serves as a transmitting end and the other set serves as a receiving end, the system complexity can be greatly simplified, and the laser radar can be miniaturized.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of radar technology, and in particular to a photonic integrated chip based on a micro-ring optical switch network. Background Technology

[0002] With the development of autonomous driving and remote sensing technologies, LiDAR has received increasing attention. Its basic architecture is similar to microwave radar, except that all components are laser-based optical devices. Although there are many different types of LiDAR on the market, most are based on mechanical rotating or MEMS architectures, which contain mechanical parts and are prone to aging. This makes them unsuitable for use in autonomous driving and related fields.

[0003] In conclusion, developing an all-solid-state lidar is crucial. Currently, many international teams are developing all-solid-state lidar based on optical phased arrays. However, this architecture presents several challenges. For example, long-range detection requires large-scale optical phased arrays, such as 512 channels or larger, which is extremely difficult for control circuitry. Furthermore, as the scale of the optical phased array increases, the optical losses on the chip also increase, contradicting the requirements for long-range detection. Therefore, a few researchers have proposed all-solid-state lidar based on optical switches. In this approach, light emitted or received by optical antennas at different locations can be deflected by lenses. This type of lidar has a simple working principle, but achieving quasi-continuous scanning still requires large-scale optical antenna arrays and numerous cascaded optical switches at the front end. Additionally, conventional lidar chips have relatively limited operating modes; a single chip can only be used for either transmission or reception, leading to greater system complexity and higher costs. Therefore, a novel optical switch network chip architecture is needed. This network should be compact, easy to control, and support multiple operating modes. Summary of the Invention

[0004] This invention provides a lidar optical chip based on a micro-ring optical switch network. The lidar optical chip, based on a micro-ring optical switch array, is more compact, simpler to control, and has lower on-chip optical loss than lidar based on an optical phased array architecture, making it a more practical all-solid-state lidar solution. Furthermore, the lidar optical chip based on the micro-ring optical switch network provided by this invention has multiple operating modes, offering more comprehensive functions and more flexible applications.

[0005] In a first aspect, the present invention provides a lidar optical chip, comprising: at least one input / output coupler, a micro-ring optical switch array, and at least one optical antenna array;

[0006] The input / output coupler is used to couple the light emitted by the laser to the chip of the lidar or to couple the light on the chip to the detector;

[0007] The micro-ring optical switch array forms an optical switch network, used to switch the light on the chip from the input waveguide to the optical antenna array.

[0008] In one embodiment, the optical antenna array includes M antennas distributed in parallel, the M antennas are divided into N optical antenna groups, and the N optical antenna groups operate simultaneously to complete the stitching of the second direction field of view, wherein the second direction is along the antenna direction.

[0009] In one embodiment, the antenna width, grating period, and duty cycle of the optical antenna group may be the same or different.

[0010] In one embodiment, the micro-ring optical switch array includes a two-dimensional micro-ring optical switch array and at least one one-dimensional micro-ring optical switch array, wherein the number of one-dimensional micro-ring optical switch arrays corresponds to the number of input / output couplers and the number of optical antenna arrays.

[0011] Each input / output coupler inputs the emitted light into the two-dimensional micro-ring optical switch array through a one-dimensional micro-ring optical switch array, and transmits the emitted light to the corresponding optical antenna array through the two-dimensional micro-ring optical switch array.

[0012] In one embodiment, the input / output coupler, the one-dimensional micro-ring optical switch array, the two-dimensional micro-ring optical switch array, and the optical antenna array are all connected by waveguides; the positions of the waveguide intersections in the two-dimensional micro-ring optical switch array are achieved by a cross-shaped waveguide structure or a double-layer waveguide, and the light between different layers of waveguides is coupled to each other by evanescent waves.

[0013] In one embodiment, the cross-shaped waveguide structure employs a double-layer waveguide, wherein the first waveguide layer of the double-layer waveguide is located on the top silicon layer of the SOI substrate, and the second waveguide layer of the double-layer waveguide is located above the first waveguide layer. There is a spacer layer between the second waveguide layer and the first waveguide layer. The first waveguide layer and the second waveguide layer transfer the light beam in the waveguide to each other through a set of opposing and overlapping trapezoidal template converters.

[0014] The refractive indices of both the first waveguide layer and the second waveguide layer are greater than the refractive index of the spacer layer.

[0015] In one embodiment, both the first waveguide layer and the second waveguide layer are TE-mode single-mode waveguides, and are either ridge waveguides or strip waveguides.

[0016] In one embodiment, the input / output coupler is an end-face coupler or a grating coupler; the micro-ring optical switch is a thermo-optical optical switch or an electro-optical optical switch.

[0017] In one embodiment, each optical switch in the micro-ring optical switch array has an independent control electrode;

[0018] Each optical switch in the one-dimensional micro-ring optical switch array has an independent control electrode, and in the two-dimensional micro-ring optical switch array, each row or column of optical switches shares a control electrode.

[0019] In one embodiment, the optical antenna array is a grating-type optical antenna, wherein the grating of the grating-type optical antenna is a second-order diffraction grating, and the grating period and duty cycle of the grating-type optical antenna are matched with the operating wavelength.

[0020] In one embodiment, the distance between each optical antenna in the optical antenna array is set according to the parameters of the lens above the chip, and the optical antennas are set at equal or non-equal intervals.

[0021] In one embodiment, the optical antenna array is connected to the output of the two-dimensional optical switch array via a bent waveguide, or directly to the output of the two-dimensional optical switch array.

[0022] In one embodiment, a protective layer is covered on all components of the lidar optical chip, the material of which has a lower refractive index than the materials of the first and second waveguides.

[0023] In one embodiment, the system further includes a lens, the number of which is the same as the number of optical antenna arrays, and is either a single lens or a group of lenses. The lens is located directly above the optical antenna array, and the optical antenna array is located at the focal plane of the lens. The lens is used to collimate the emitted beam and achieve angular deflection.

[0024] In another aspect, the present invention provides a lidar scanning method applied to the aforementioned lidar optical chip, comprising:

[0025] The emitted light is switched to a specific optical antenna in a specific optical antenna array via a micro-ring optical switch array, and the first direction deflection of the emitted light is achieved in conjunction with an external lens; wherein, the specific optical antenna array includes M antennas distributed in parallel, and the M antennas are divided into N groups;

[0026] The emitted light is deflected in a second direction by changing its wavelength and transmitting it from a single optical antenna. By changing the wavelength and switching between different optical antennas, a two-dimensional scanning range can be achieved.

[0027] This invention provides a lidar optical chip that supports multiple operating modes. It can be configured into a multi-optical-path system as needed. For example, when the lidar optical chip includes two input / output couplers and two sets of optical antenna arrays, a dual-optical-path system is obtained. This dual-optical-path system can function entirely as a transmitter, enabling field-of-view stitching and increasing the lidar's field of view. It can also function entirely as a receiver, doubling the receiving area and enhancing reception capabilities. Furthermore, the dual-optical-path system can be configured with one set as a transmitter and the other as a receiver, significantly simplifying system complexity and enabling miniaturization of the lidar. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A schematic diagram of the structure of a lidar optical chip based on a micro-ring optical switch network provided in an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the structure of a single micro-ring optical switch in a lidar optical chip based on a micro-ring optical switch network, provided in an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of a one-dimensional micro-ring optical switch array based on a micro-ring optical switch network for a lidar optical chip provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of a two-dimensional micro-ring optical switch array based on a micro-ring optical switch network for a lidar optical chip provided in an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of the structure of a micro-ring optical switch network lidar optical chip for adjusting the optical antenna spacing by bending a waveguide, provided in an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of a lidar optical chip with a single lens based on a micro-ring optical switch network, provided in one embodiment of the present invention.

[0035] Figure 7 This is a schematic diagram of the structure of a lidar optical chip with two lenses based on a micro-ring optical switch network, provided in one embodiment of the present invention.

[0036] Figure 8This is a schematic diagram of all emission modes of a lidar optical chip provided in one embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of the longitudinal field of view stitching of a lidar optical chip according to an embodiment of the present invention;

[0038] Figure 10 This is a schematic diagram of all receiving working modes of a lidar optical chip provided in one embodiment of the present invention;

[0039] Figure 11 This is a schematic diagram of a laser radar optical chip operating in a one-transmit and one-receive mode according to an embodiment of the present invention.

[0040] 11-Input / Output Coupler 12-Input / Output Coupler 21-One-Dimensional Micro-Ring Optical Switch Array 22-One-Dimensional Micro-Ring Optical Switch Array 3-Two-Dimensional Micro-Ring Optical Switch Array 41-Optical Antenna Array 42-Optical Antenna Array 5-Bendable Waveguide 6-Lens 71-Transmit Beam 72-Receive Beam Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Figure 1 This is a schematic diagram of the structure of the lidar optical chip provided in Embodiment 1 of the present invention; as shown Figure 1 As shown, the lidar optical chip provided in this embodiment mainly includes: at least one input / output coupler 11 or 12, an input / output coupler micro-ring optical switch array, and at least one optical antenna array (two optical antenna arrays are used as an example in the figure, namely a one-dimensional micro-ring optical switch array optical antenna array 41 and an optical antenna array 42). Generally, the number of optical antenna arrays corresponds to the number of input / output couplers.

[0043] The lidar optical chip provided in this embodiment supports multiple operating modes. It can form a multi-optical-path system according to requirements, and each optical path can work independently. For example, when the lidar optical chip includes two input / output couplers and two sets of optical antenna arrays, a dual-optical-path system is obtained. The entire dual-optical-path system is used as a transmitter, which can realize field-of-view stitching and increase the lidar's field of view. The entire dual-optical-path system can also be used as a receiver, which can double the receiving area and enhance the receiving capability. The dual-optical-path system can also be configured with one set as a transmitter and the other as a receiver, which can greatly simplify the system complexity and enable the miniaturization of the lidar.

[0044] Optionally, in other embodiments, when the LiDAR optical chip includes three input / output couplers and three optical antenna arrays, a three-way optical system is obtained. To cover a larger field of view, the optical antenna array of each optical system can be set to correspond to a 120-degree field of view. Similarly, when the LiDAR optical chip includes four input / output couplers and four optical antenna arrays, a four-way system is obtained. To cover a larger field of view, the optical antenna array of each optical system can be set to correspond to a 90-degree field of view. It should be understood that when the number of input / output couplers and optical antenna arrays is other, the principle is similar to that of two, three, or four, and will not be elaborated here. Furthermore, it is understood that during LiDAR scanning, not all situations require scanning a 360-degree field of view. To meet different needs, the optical antenna arrays can be set unevenly. For example, the field of view of some antennas can overlap, and some optical antenna arrays can be cross-set, etc.

[0045] Optionally, each optical switch in the micro-ring optical switch array has an independent control electrode. Alternatively, if the micro-ring optical switch array includes a one-dimensional micro-ring optical switch array and a two-dimensional micro-ring optical switch array, then each optical switch in the one-dimensional micro-ring optical switch array has an independent control electrode, and in the two-dimensional micro-ring optical switch array, each row or column of optical switches shares a single control electrode.

[0046] Optionally, the micro-ring optical switch array includes a two-dimensional micro-ring optical switch array 3 and at least one one-dimensional micro-ring optical switch array. The number of one-dimensional micro-ring optical switch arrays corresponds to the number of input / output couplers and the number of optical antenna arrays. Each input / output coupler inputs emitted light into the two-dimensional micro-ring optical switch array through a one-dimensional micro-ring optical switch array, and transmits the emitted light to the corresponding optical antenna array through the two-dimensional micro-ring optical switch array. When multiple micro-ring optical switches are connected in parallel, the one-dimensional optical switch array is formed, and its structure is as follows: Figure 3As shown, the input waveguide is a row waveguide, with several micro-rings arranged side-by-side on one side. Each micro-ring has an independent output waveguide on its own side, and each micro-ring is individually controlled, allowing the input light to be switched from the row waveguide to a specific column waveguide. Furthermore, when multiple column waveguides are arranged in parallel, and several micro-ring optical switches are arranged on one side of each column waveguide, a two-dimensional micro-ring optical switch array 3 can be formed, as shown in Figure 3. Figure 4 As shown, each micro-ring optical switch has two output waveguides, with S-shaped outputs on the left and right sides. Micro-ring optical switches in the same row of waveguides are staggered by a certain distance, forming multiple sets of output waveguides. The scale of the two-dimensional micro-ring optical switch array 3 can be expanded according to specific needs, simply by increasing the number of waveguides and the number of optical switches on each waveguide. The one-dimensional optical switch array and the two-dimensional micro-ring optical switch array together constitute the micro-ring optical switch network of the lidar optical chip, used to switch the light on the chip from the input waveguide to a specific optical antenna.

[0047] In one embodiment, the optical antenna array includes M parallel optical antennas, where the value of M is determined by the number of output terminals of the optical switch network. These M antennas are divided into N optical antenna groups, each with M / N antennas, and each optical antenna group is independent of the others. Optionally, the various optical antenna groups can have the same structure or different structures.

[0048] For example, the antenna width, grating period, duty cycle, etc., in each optical antenna group can be the same or different. The two antennas output from the same micro-ring in the optical antenna array 41 and optical antenna array 42 are independent of each other, and the structures of these two antennas can be the same or different. The antenna spacing in the two optical antenna arrays can be the same or different.

[0049] Furthermore, the optical antenna array and the two-dimensional optical switch network 3 can be directly connected or indirectly connected through the bent waveguide 5, such as... Figure 5 In the second embodiment of the invention shown, the output of the two-dimensional optical switch network 3 is connected to both the optical antenna array 41 and the optical antenna array 42 via curved waveguides. The spacing between the optical antennas can be adjusted using the curved waveguides, and can be either equal or non-equal.

[0050] When the lidar optical chip includes two input / output couplers and two sets of optical antenna arrays, it can form two optical path systems. The input / output coupler 11, the one-dimensional micro-ring optical switch array 21, the two-dimensional micro-ring optical switch array 3, and the optical antenna array 41 form a complete optical path system; the input / output coupler 12, the one-dimensional micro-ring optical switch array 22, the two-dimensional micro-ring optical switch array 3, and the optical antenna array 42 also form a complete optical path system. The two optical path systems share the two-dimensional micro-ring optical switch array 3, and the light propagates in opposite directions in the waveguide.

[0051] In one embodiment, when the chip is used for transmission, the input / output coupler 11 couples the light emitted by the laser to the lidar optical chip or couples the light received by the chip to the detector; the one-dimensional micro-ring optical switch array 21 switches the input light from the row waveguide to a specific column waveguide and transmits it to the two-dimensional micro-ring optical switch array 3; the two-dimensional micro-ring optical switch array 3 switches the light input from the one-dimensional micro-ring optical switch array 21 to a specific row waveguide and outputs it to the optical antenna array 41; the optical antenna array 41 transmits the light into space. The optical path system composed of the input / output coupler 12, the one-dimensional micro-ring optical switch array 22, the two-dimensional micro-ring optical switch array 3, and the optical antenna array 42 operates on the same principle.

[0052] In one embodiment, the input / output coupler, the one-dimensional micro-ring optical switch array, the two-dimensional micro-ring optical switch array, and the optical antenna array are all connected via waveguides. The waveguide intersections in the two-dimensional micro-ring optical switch array are achieved through a same-layer cross-shaped waveguide structure or a double-layer waveguide. Light from different waveguide layers couples with each other via evanescent waves. The cross-shaped waveguide structure employs a double-layer waveguide. The first waveguide layer of the double-layer waveguide is located on the top silicon layer of the SOI substrate, and the second waveguide layer is located above the first waveguide layer. There is a spacer layer between the second waveguide layer and the first waveguide layer. The first waveguide layer and the second waveguide layer transfer the beam in the waveguide to each other through a set of opposing and overlapping trapezoidal template converters. The refractive indices of both the first and second waveguide layers are greater than the refractive index of the spacer layer. Both the first and second waveguide layers are TE-mode single-mode waveguides, with a ridge waveguide or strip waveguide shape. This structure allows for flexible switching of light waves in the optical path and prevents crosstalk.

[0053] In one embodiment, when the chip is used for receiving, the optical path is reversed. The signal light is input from the optical antenna, switched through the optical switch network to the input / output coupler, and finally detected by the detector. The basic component of the lidar optical chip based on the micro-ring optical switch network is the micro-ring optical switch, the specific structure of which is as follows: Figure 2 As shown, a waveguide is placed on each side of a micro-ring waveguide. When the micro-ring is not resonant with respect to the operating wavelength, the input light will not be transmitted through the micro-ring to the other waveguide. When the refractive index of the micro-ring is adjusted to make it resonate, the input light will be transmitted through the micro-ring to the other waveguide. This invention does not limit the materials of the devices on the chip. Typically, the device materials can be silicon, silicon dioxide, silicon nitride, polycrystalline silicon, etc.

[0054] In one embodiment, the lidar optical chip based on a micro-ring optical switch network, in addition to the on-chip devices described above, also includes lenses. The number of lenses is the same as the number of optical antenna arrays. The lidar optical chip may include one or a group of lenses, such as... Figure 6 In the third embodiment of the invention shown, a lens 6 is disposed above the chip; the lens 6, which matches the optical antenna array, can be a single lens or a lens group, located directly above the optical antenna, covering the entire optical antenna array, and the optical antenna array is located on the focal plane of the lens. The distance between each antenna in the optical antenna array 41 and optical antenna array 42 on the chip is set according to the parameters of the lens above the chip, and can be equal spacing, Gaussian distribution, or other forms.

[0055] Furthermore, since the devices on the lidar optical chip are not symmetrical, the optical antenna arrays 41 and 42 are not aligned with the lens 6, which often affects the chip's performance. To be more flexible and fully utilize the advantages of the lidar optical chip based on a micro-ring optical switch network provided by this invention, a small lens can be placed above each of the optical antenna arrays 41 and 42. The parameters of the lens match the parameters of the optical antenna array below, and can be freely set according to specific needs. That is, the distance between each optical antenna in the optical antenna array is set according to the parameters of the lens above the chip, and the optical antennas can be set at equal or non-equal intervals. Figure 7 As shown, this is a lidar optical chip based on a micro-ring optical switch network with two lenses, which is an embodiment of the present invention.

[0056] In addition, the fourth embodiment of the invention provides multiple working modes, including: all transmission, all reception, and one transmission and one reception.

[0057] Specifically, the "all emission" refers to using both optical path systems on the chip to emit beams 71 outwards, with the chip's input terminal connected to a laser, such as... Figure 8 As shown. Specifically, the input light is switched via an optical switch network to optical antennas of the same structure in different groups of the optical antenna array, and the external lens 6 is used to achieve lateral deflection of the emitted beam, where lateral refers to the direction perpendicular to the optical antenna array; the wavelength of the input light is changed, and after longitudinal deflection is completed by emitting it from a single optical antenna, as shown... Figure 9As shown, the first antenna achieves a field of view from 0° to θ1°. By switching to other optical antennas with different structures in the same group through the optical switch network, the transmitted beam can be further deflected longitudinally, i.e., from θ1° to θ2°, until all optical antennas in the same group have worked once. If there are 4 antennas in an optical antenna, the field of view corresponding to the last antenna is from θ3° to θ4°, thus completing the entire range of longitudinal deflection of a single optical antenna array from 0° to θ4°. The longitudinal direction refers to the direction along the optical antenna array.

[0058] Furthermore, when the chip operates in all emission modes, the input / output coupler, micro-ring optical switch network, and optical antenna array work together to achieve a longitudinal field of view from 0° to θ°, where the value of θ can be positive or negative, depending on the emission direction of the optical antenna relative to the working wavelength beam; the input / output coupler, micro-ring optical switch network, and optical antenna array work together to achieve a longitudinal field of view from -θ° to 0°; the two optical path systems can work simultaneously or in a time-division manner, and the overall longitudinal field of view of the lidar optical chip is extended from -θ° to θ°.

[0059] The aforementioned full receiving mode uses both optical path systems on the chip to receive beam 72, such as... Figure 10 As shown. The chip input is connected to the detector. The input / output coupler 11, the micro-ring optical switch network, and the optical antenna array 41 work together to receive the light signal reflected from the target object from the optical antenna array 41 onto the chip and finally transmit it to the input / output coupler 21, where it is detected by the detector connected to it. The input / output coupler 12, the micro-ring optical switch network, and the optical antenna array 42 work together to receive the light signal reflected from the target object from the optical antenna array onto the chip and finally transmit it to the input / output coupler 12, where it is detected by the detector connected to it. Both optical path systems are used for reception simultaneously, doubling the receiving aperture and enabling the detection of twice the reflected signal.

[0060] The aforementioned one-to-one transmit and one-to-receive mode uses two optical path systems on the chip: one for transmitting beam 71 and the other for receiving beam 72. Figure 11 As shown. The optical path systems used for transmitting and receiving are interchangeable. When the input / output coupler 11 is connected to the laser and the input / output coupler 12 is connected to the detector, the input / output coupler 11, the micro-ring optical switch network, and the optical antenna array 41 are used together to transmit the laser into space and scan the target object. The input / output coupler 12, the micro-ring optical switch network, and the optical antenna array 42 are used together to transmit the light signal 72 reflected back from the target object to the detector for detection. The two optical path systems work simultaneously.

[0061] This invention provides a lidar optical chip, comprising: two input / output couplers 11 and 12, two one-dimensional micro-ring optical switch arrays 21 and 22, a two-dimensional micro-ring optical switch array 3, and two sets of optical antenna arrays 41 and 42. The two on-chip optical path systems are independent and do not affect each other. The lidar optical chip based on the micro-ring optical switch network provided by this invention supports multiple operating modes, including: both optical path systems are used as transmitters, enabling field-of-view stitching and increasing the lidar's field of view; both optical path systems are used as receivers, doubling the receiving area and enhancing receiving capability; one optical path system is used as a transmitter and the other as a receiver, greatly simplifying system complexity and enabling lidar miniaturization.

[0062] Optionally, a protective layer is applied to all components of the lidar optical chip, and the refractive index of the material of the protective layer is lower than that of the materials of the first and second waveguides.

[0063] Based on the same inventive concept, one embodiment of this application also provides a lidar scanning method, applied to the lidar optical chip as described above. The method includes: switching the emitted light to a certain optical antenna in a certain optical antenna array through a micro-ring optical switch array, and cooperating with an external lens to achieve a first direction deflection of the emitted light beam; wherein, the certain optical antenna array includes M antennas distributed in parallel, and the M antennas are divided into N groups; changing the wavelength of the emitted light and emitting it from a single optical antenna to complete a second direction deflection, thereby achieving a two-dimensional scanning range by changing the wavelength and switching different optical antennas.

[0064] It should be noted that the scanning method described above refers to the two-dimensional scanning process achieved by each individual optical system of the lidar optical chip. When the lidar optical chip of this application includes two or more optical systems, each optical system can independently achieve the two-dimensional scanning process. Each optical system can operate in a time-sharing manner according to the system control signal.

[0065] In one embodiment, the scanning method further includes: receiving the reflected echo through an external lens in conjunction with an optical antenna, changing the wavelength and switching different optical antennas so that the reflected echo is transmitted in reverse from the optical antenna along the original transmission optical path to the input coupler, and finally detected by the detector.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lidar optical chip, characterized in that, include: Multiple input / output couplers, micro-ring optical switch array, and multiple optical antenna arrays; The input / output coupler is used to couple the light emitted by the laser to the chip of the lidar or to couple the light on the chip to the detector; The micro-ring optical switch array forms an optical switch network, which is used to switch the light on the chip from the input waveguide to the optical antenna array. The micro-ring optical switch array includes a two-dimensional micro-ring optical switch array and multiple one-dimensional micro-ring optical switch arrays. The number of one-dimensional micro-ring optical switch arrays corresponds to the number of input / output couplers and the number of optical antenna arrays. Each input / output coupler inputs emitted light into the two-dimensional micro-ring optical switch array through the corresponding one-dimensional micro-ring optical switch array, and transmits the emitted light to the corresponding optical antenna array through the two-dimensional micro-ring optical switch array.

2. The lidar optical chip according to claim 1, characterized in that, The optical antenna array includes M antennas distributed in parallel. The M antennas are divided into N optical antenna groups. The N optical antenna groups operate in shifts to complete the stitching of the second direction field of view, wherein the second direction is along the antenna direction.

3. The lidar optical chip according to claim 2, characterized in that, The antenna width, grating period, and duty cycle of the optical antenna group may be the same or different.

4. The lidar optical chip according to claim 1, characterized in that, The input / output coupler, the one-dimensional micro-ring optical switch array, the two-dimensional micro-ring optical switch array, and the optical antenna array are all connected by waveguides; the waveguide intersections in the two-dimensional micro-ring optical switch array are achieved by a cross-shaped waveguide structure or a double-layer waveguide, and the light between different layers of waveguides is coupled to each other by evanescent waves.

5. The lidar optical chip according to claim 4, characterized in that, The cross-shaped waveguide structure employs a double-layer waveguide. The first waveguide layer of the double-layer waveguide is located on the top silicon layer of the SOI substrate, and the second waveguide layer is located above the first waveguide layer. There is a spacer layer between the second waveguide layer and the first waveguide layer. The first waveguide layer and the second waveguide layer transfer the beam in the waveguide to each other through a set of opposite and overlapping trapezoidal template converters. The refractive indices of both the first waveguide layer and the second waveguide layer are greater than the refractive index of the spacer layer.

6. The lidar optical chip according to claim 5, characterized in that, Both the first and second waveguide layers are TE-mode single-mode waveguides, and their shapes are either ridge waveguides or strip waveguides.

7. The lidar optical chip according to claim 1, characterized in that, The input / output coupler is an end-face coupler or a grating coupler; The micro-ring optical switch is either a thermo-optical optical switch or an electro-optical optical switch.

8. The lidar optical chip according to claim 1, characterized in that, Each optical switch in the micro-ring optical switch array has an independent control electrode; Each optical switch in the one-dimensional micro-ring optical switch array has an independent control electrode, and in the two-dimensional micro-ring optical switch array, each row or column of optical switches shares a control electrode.

9. The lidar optical chip according to claim 1, characterized in that, The optical antenna array is a grating-type optical antenna, wherein the grating of the grating-type optical antenna is a second-order diffraction grating, and the grating period and duty cycle of the grating-type optical antenna are matched with the operating wavelength.

10. The lidar optical chip according to claim 1, characterized in that, In the optical antenna array, the distance between each optical antenna is set according to the parameters of the lens above the chip, and the optical antennas are set at equal or non-equal intervals.

11. The lidar optical chip according to claim 1, characterized in that, The optical antenna array is connected to the output of the two-dimensional optical switch array via a bent waveguide, or directly to the output of the two-dimensional optical switch array.

12. The lidar optical chip according to any one of claims 1-11, characterized in that, A protective layer is applied to all components of the lidar optical chip. The refractive index of the material of the protective layer is lower than that of the materials of the first and second waveguides.

13. The lidar optical chip according to any one of claims 1-11, characterized in that, Also includes: The lens, which is the same number as the optical antenna array, is a single lens or a group of lenses. The lens is located directly above the optical antenna array, and the optical antenna array is located on the focal plane of the lens. The lens is used to collimate the emitted beam and achieve angular deflection.

14. A lidar scanning method, applied to a lidar optical chip as described in any one of claims 1-13, characterized in that, The emitted light is switched to a specific optical antenna in a specific optical antenna array via a micro-ring optical switch array, and the first direction deflection of the emitted light is achieved in conjunction with an external lens; wherein, the specific optical antenna array includes M antennas distributed in parallel, and the M antennas are divided into N groups; The emitted light is deflected in a second direction by changing its wavelength and transmitting it from a single optical antenna. By changing the wavelength and switching between different optical antennas, a two-dimensional scanning range can be achieved.

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